Improved pivement



B. B. HOTCHKISS.

Wood Pavement.

No. 63,162. Patented March 26, 1867.

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I Letters Patent No. 63,162, dated March 26, 1867.

IMPROVED PAVEMENT.

' at: fiilphule infant in in ilgra items 5 .3mmzuit making and at its same.

TO ALL WHOM IT MAY CONCERN: I

Be it known that I, B. HO'IQHKISS, of the city and county of New York, and State of New York, have invented certain new and useful Improvements inv Pavements; and I do hereby declarev that the following is a full and exact description thereof. p I

I will proceed to describe what I oonsider'tl-ife best means of carrying out my invention. The accompanying drawings form a part of this specification. p I 1 Figure 1 is a vertical section across a portion of pavement on a scale about half size.

Figure 2 is a plan view of one of the underlying supports which I employ in combination.

Figure 3 is a vertical section throughsaid underlying support; and 1 Figure 4 is a plan view on a small scale showing the arrangement of the severalpieces in which the main portions of my pavement is formed, and more especiallythe arrangement of the underlying supports relatively to the other parts. I

Similar letters of reference indicate like parts in all the figures where they occur.

A and B are blocks of wood placed end uppermost. D and D are iron" castings so constructed as to form cells, in which the wood blocks A and B are loosely placed. The base portion or flooring of the cells is indi-- cated by D. The sidesor webs are indicated by D. The blocks A and Bare-each an inch or so smaller in their horizontal dimensions than the cells in which they are introduced. The base-plate D may have large holes in the bottom, not represented, if desired; and'the webs D may be depressed at intervals. This expedient will economize metal and thus lower the cost of the pavement. It will be observed that the blocks Aand B are crowded close against the web D on one side, and that all the space due to the difference in size between the wood and'the cell is on the opposite side.- G represents a quantity of saw-dust, which is deposited in the bottom of the space thus provided. I H represents a quantity of gravel or broken stone, which is introduced into the space above the saw-dust G and rammed down with great force in the act of constructing the pavement. The best'mode of effecting this is to introduce the gravel loosely at a single operation or at several successive operations, and to place thereon a thin set or slab of iron provided with a suitable connection by which to handle it, and to allow a strong man to strike on the upper edge of the iron with a maul of wood or metal. After the space between the web D and the block A or B is thus filled up to the top of the web D, more of the gravel is introduced loosely and similarly packed; and it is practicable to use awider set or crowding instrument after the filling has progressed above the top of the web. All the interstices between the several blocks may in. this manner be filled nearly or quite to the top. Cements of variouskinds,-a's tar, rosin,-e ement, asphalt, or analogous material, may be applied either with the gravel or before or after, if desired. The saw-dust G should be in a damp condition when it is introduced in the cells, and is thus crowded down by the strong pressure, as above described, upon the superineumben't gravel or broken' stone. The saw-dust of most woods thus conditioned cakes together and forms a very hard mass. If the-displacement of any part subsequently looscns'or disturbs the hard cake thus formed the material, by its peculiar nature, is likely to form again into a complete cake on. the next occasion when it is thoroughly wettedand subsequently dried, or partially dried. Pavements are of course liable in ordinary climates to be subjected to alternate wettings and dryings, and these qualities of sawdust'arevery important in forming a packing at. the place represented to prevent the gravel H- from working under the bottoms of thc'blecks A and B, when, as will sometimes be the case, the blocks becomea little loose- It will be observed that the blocks A and B neednotbe very accurately fitted. They may vary in size within reasonable limits, and may even vary in shape from the size of the cells. It is possible, in carrying out my invention, with inferior materials to fill, or nearly fill, the cells in the manner above described with several chunks or irregular masses of wood, as, for example, with several pieces of round wood, such as is formed by simply saw.- ing up small branches of oak, pine, or other suitable wood. In such cases care must be taken, in applying the gravel, to fill the interstices with tolerable perfection with this material; In all cases I prefer to put saw-dust, G, in the bottoms of the cells after the wood is applied and before the gravel is introduced. But some portion of the benefits of my invention may be realized without the introducticnof any such packing. Other material. than saw-dust may be applied with some success; thus, for example, sea weed, common wood-shavings, fine tan,

moss, dried leaves, grasses of various kinds, and the like, may be employed to form a fibrous packing which wil cake together and prevent the working of anyof the lumps of gravel below the wood. One of the main sources of difficnlty in the use of wood pavement is due to thechange of volume of the blocks A and B or the equivalent masses of wood filling placed with the grain vertically, as represented, du'eto the changes of conditionsin regard to moisture. A continued rain, by saturating and swelling the wood, causes it to fill the cells more tightly and crowd the adjacent gravel partially into the surface of the wood. A verythorongh drying of the pavement, as is liable to occur in many situations, tends on the contrary to loosen the blocks by shrinking thenn The action of wheels and of the feet of animals upon my pavement tends to continually pack down the gravel under such conditions, so that the tendency is to compress'the blocks more and more, and thus to maintain a very dense and perfect condition in the wood; but as the blocks are'obviously liable to work more or less Idccm it Well to provide the packing G, as represented. The cells maybe nearly rectangular in section, or they may be very greatly elongated, was to contain two, three, or even twenty square blocks of wood in a single cell, in which cases I can,iifpreferred, pack a small quantityof gravel before described between each of the several blocks in such long cells;- but I prefer under ordinary circumstances to apply the blocks, if-th'ey are of proper form, tightly together, and to pack the grav'elly matter only along the faces which arepr'escntcd against the webs D. Where cross-webs are introduced so as to divide each piece of pavement into agreat number of separate cells I prefer to so distribute the webs D that the blocksshall break joints with each other, an arrangement which will be readily understood by good mechanics without a figure. I prefer to make the several pieces of pavement in elongated shapes and with the ends oblique. Fig. 4 shows the general form of the pieces of pavement, but omits to designate the arrangement ofthe blocks therein. The purpose of fig; 4 is to show another feature of my invention, that is to say, my peculiar means of supporting the corners or angles in the street where the several pieces of mypavement cometogether. I and J represent two pieces of wood Theymay be pine boards saturated or not with tarry or other preservative, matter. These parts are placed one upon the other under the several corners of the pieces ,inithe positionsrepresented; and I' talce care to so lay the pieces I and J that the grain of the uppermost piece I shall cross the grain of the lowermost piece J. This provides against the liability of either piece-to split. The pieces I and J may be pinned, nailed, or otherwise fastened together, if preferred; and they may be fastened to the pavement by nails or other suitable devices projecting upward from the upper 'faceof the uppermost piece I into the joints betwecnthe several pieces of pavement, or into any suitable hole or holes provided in the adjacent pieces. 1 can, if preferred, in any situations pack the spaces between the blocks A and B and the webs D with short wood pieces, providing for the'purpose anumber of such thin pieces of'wood of variable thickness tomatch the variations in" the spaces to be filled. I'can drive these wood packings down in the same manner as beforc described, and they will serve a good purpose, but I prefer generally to use gravel or analogous gritty matter, not only above the tops of the webs D but also down the sides of these Webs nearly to the bottom, as described.

Having now 'fully described my'inv'ention, what I claim as. new therein, and desire to secure by Letters Patent, is as follows:

1. Iclaim fitting wood blocks in cast-iron cells or, cavities by employing blocks of less size than the cells and driving a packing H; into the spaces between the blocks and the sides of the cell, substantially as and for the purpose herein specified.

2. I claim, in connection with the above, the stopping material G introduced in the bases of the cells opposite the bottoms of the blocks, and adapted to prevent the workingof any of the packing under the wood, substantially as herein specified.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

' 1B. B. HOTOHKISS.

Witnesses:

WM. 0. Der, F. A. -HADIOKER. 

